And I'm Renee Montagne. It's been more than a year since Edward Snowden fled the country with top-secret, digital documents from the National Security Agency, and revelations about what he took keep coming. The latest appeared yesterday, in the online publication The Intercept. Its headline is, "Meet The Muslim-American Leaders The FBI And NSA Have Been Spying On," and it was co-written by Glenn Greenwald. Five prominent Muslim citizens are profiled. And all five say they were spied on because they are Muslims. To look at these claims more closely, we're joined by NPR national security correspondent David Welna. Good morning.

DAVID WELNA, BYLINE: Good morning, Renee.

MONTAGNE: What's the evidence we're getting from Snowden in this new report?

WELNA: Well, you know, the NSA says it won't comment on alleged surveillance targets. This is all based on a document Snowden took called "FISA Recap," which suggests that this is connected to the Foreign Intelligence Surveillance Act. Curiously, it had none of the classification codes such an internal document would normally have. It's basically a spreadsheet. And it lists nearly 7,500 email addresses of people or entities the NSA allegedly spied on between the years 2002 and 2008, when George W. Bush was still president. And even though spy agencies are expected to spy only on foreigners outside the country, this spreadsheet shows at least 200 emails of people living in the U.S. who were being targeted during at least some of that time.

MONTAGNE: So this seems to have happened up through 2008, as you say. Was it legal, at the time, for the NSA to do this?

WELNA: Well, it would've been provided there were orders from a secret intelligence court allowing the NSA to spy on individuals living in the U.S. But this new story notes that Snowden apparently did not take with him any of those court orders if, in fact, they existed. The NSA insists it has only acted within the law. I did speak with someone yesterday who knows the NSA's inner-workings quite well. And he told me that any warrant issued for domestic spying on an American would have to have met a standard of probable cause, and it would have had to show two things - one that the person to be spied on was an agent of a foreign power, and two - that the person was also in possible violation of U.S. criminal law.

MONTAGNE: Although, these five Muslim-Americans profiled in this piece are - or were and are all highly visible public figures.

WELNA: That's right. And all five of them insist that they did nothing that would warrant being spied on. One of them is a Republican who worked in the George W. Bush Administration. Another was a Democratic staffer on Capitol Hill who later represented an Islamic charity whose assets had been frozen. Another was a college professor who thinks he was spied on because of his friendship with a colleague convicted of helping an Islamic jihadist group. Another was an Iranian-American college professor who twice ran for the presidency of Iran. And the fifth was the co-founder of the Council on Islamic-American Relations, it's a group that also has ties to Hamas which the U.S. considers a Palestinian terrorist organization. But to be clear, we simply don't have enough information from the one document in this story to know why any of these people's emails would've been collected.

MONTAGNE: And of course, we've learned a lot about spying in the past year. Germany's Angela Merkel having her cell phone tapped, millions of Americans having their phone records collected by the NSA. How important is this latest revelation about alleged spying on Muslim-Americans?

WELNA: Well, it's significant in two ways. It's the first time we've had names named of Americans targeted by the NSA, so we may well be seeing some or all of those named suing the spy agency since this would likely give them the legal standing to do so. And it also raises the question of whether these people were singled out because of their Muslim faith or their political activity. The document in this report does not prove these people were targeted because they were Muslim-Americans. That's simply what they contend. Yesterday in response to the story, the Office of the Director of National Intelligence put out a segment saying quote, "No U.S. person can be the subject of surveillance based solely on First Amendment activities." The implication being that there had to be something else. But what that is we just don't know because there are no documents from Snowden that spell that out, and the NSA is saying no comment.